Combination coal and gas range.



H. C.. MAUL.

COMBINATION COAL AND GAS RANGE.

APPLICATION FlLED AUG428. I914 Patented Sept. 21-, 1915..

5 SHEETS-SHEET 1.

H: c. MAUL. COMBINATION COAL AND GAS RANGE.

' APPLICATION FILED AUG.ZB. I914.

Patented Sept. 21, 1915.

5 SHEE S-SHEE'I 2.

APPLICATION HLED AUGJB. 1914.

' Patented Sept. 21, 19.15.

5 SHEETS-SHEET 3..

H. C. MAUL.

COMBINATION COAL AND GAS RANGE.

APPLICATION FILED AUGJ28. 1914.

1,15%,038. Patented sept. 21, 1915.

5 SHEETS-SHEET 4.

News rzknsvmc Limo. msmnarm n. c.

H. C. MAUL.

COMBINATION GOAL AND GAS RANGE.

APPLlCATlON FILED AUGJB. I914.

Patented Sept. 21, 1915.

5 SHEETS-SHEET 5 l vbbwem '57544. W

TTEE TATES PATENT OFFICE.

HENRY C. MAUL, OF DETROIT. 'MICHIGAN. ASSIGNOR TO THE MICHIGAN STOVE COM- PANY, -OF DETROIT, MICHIGAN. A CORPORATION OF MICHIGAN.

COMBINATION COAL AND GAS RANGE.

Specification of Letters Patent.

*atented Sept. 21, 1915.

Application filed August 28, 1914. Serial No. 859,022.

To aZZ "111710771 it 122 cry mm Be it known that I. HENRY C. MAUL, a citizen of the United States of America, residing at Detroit. in the county ofll ayne and State of Michigan, have invented certain new and useful Improvements in Cour bination Coal and Gas Ranges, of which the following is a specification, reference being had therein to the acconupanying drawings. This invention relates to a combination coal and gas range and particularly to that class of stove in which the same oven is heated by means of products of combustion of gaseous fuel or by means of the radiated or conducted heat derived from the com biiistion of coal or other solid fuel.

In ranges of this class heretofore used, it has been found that the construction of the oven and the arrangement of fines. dampers and burners is not conducive to best results. Therefore I have devised a stove which pos sesses among its salient features the following:-lfirst, a range that permits ofa change of fuel without changing the range. and that has an oven that can be heated by a coal fireQnatural orartificial gas, or both gas and coal. Second, a draft equalizing damper in the smoke fine of the coal range or stove to prevent variations in the chimney draft from effecting the operation of the range oven when gaseous fuel is utilized. Third, a flue box that is employed. when natural gas is used as a fuel, the flue box cooperating with solid grids in preventing poisonous gas fumes from escaping into a room. Fourth, an opening in the bottom of an oven to admit gas and air to an oven burner with its side walls tapered outward and exposed to serve functionally as a radiator when the burner is removed and the bottom of the openingis closed with a stopper.

The'above are a few of the novel features and in the general make up of the stove or range. the. parts are constructed with a view of'reducing the cost of manufacture and at the same time retain the features'by which durability, simplicity. and the ease and accuracf: of assembling are secured, and with such ends in view. my invention consists. in the novel construction. combination and arrangement of parts to be hereinafter specifically described: the specification being di rected more particularly to the preferred fornr of construction illustrated bv the drawings, wherein V Figure l is a plan of a combination coal and gas range with the grids of'the gas range removed; Fig. 2 is a rear elcvation of the combination coal and gas range: Fig. 3 is a front elevation of the same, partlVliroken awa v and partly in longitudinal section: Fig. l is a cross sectional view taken on the line V-V .of Fig. l: and Fig. 5 is a similar view taken on the line VIYI of Fig. 3 with the burner removed and a stopper or guard in position.

In a combination coal and gas range which embodies the leading chaiiicteristihs of m v invention.-there is present a complete solid fuel burning unit whiclris generally designated b v the reference numeral 1 and occupies one end of the stove structure. This coal burning unit has a wall 2 forming an end wall of a substantially rectangular oven located within the stove casing and col-uprising bottom wall 3. an end wall 4, a rear wall 5 and a top wall 6. The bottom wall is spaced from the bottom 7 of the stove casing to provide a horizontal flue 8. The bottom 7 of the casing has a tube 9 extending into the fine 8 and serving as an air inlet. Connecting with the tube 9 is a depending frusto conical hollow tube 10, connected to the bottom wall 3 of the oven and communicating with the tube 9 to admit air to the burner as is essential when gaseous fuel is used as a heating medium for the oven.

The end wall 4' of the oven is in proximity to the end wall 11 of the stove casing and cooperates therewith in pro'iding a "ertical end flue 12. said line having the lower end thereof in communication with the horizontal flue 8. i

The top wall 6 of the oven is spaced from the grids or top 16 of the stove casing to provide a top horizontal line '17 in connnunication with the fire box of the coal burning unit 1. The walls 2. 3. L and 6 of the oven adjoin the front 'wall 1S ofthe stove casing and said front wall has a hinged door 19 whereby eas v access can be had to the interior of the oven. The rear wall ll of the casing and the offset portion 13 of said wall has chimney flues 20 and 21 in communication with-a chimney or exhaust pipe 22.

The flue 21'communicates with the rear end of the horizontalfiue- 8 as best shown in Fig.

5,, and a partition 23 has an opening 24 adapted to be closed by a damper 25 in the form of a pivoted shutter that is opened backward into the flue 20 and is closed through the medium of a crank shaft 26 in.

the top wall 16,0f the stove casing contiguous' to the chimney 22. The crank shaft 26 constitutes a conventional means of opening and closing the damper from the exterior of the stove casing, and when the damper 25 is ,closed, as shown in Fig. 5, there is a complete coal burning stove or range in which the products of combustion circulate.

around the oven, pass into the flues 21 and 20 and escape through the chimney pipe 22.

During the use of solid fuel, a closure 27 is placed in the conical tube 10 of the oven flush with the bottom thereof whereby air cannot enter the oven but on account of the flaring walls of the tube 10 the heat from I the flue 8 is radiated into the oven so as to counteract the coldness of the unheated cover 27.

Reference -will now be ha d to the gas range portion of the stove and by referring to Figs. 3 and 5, it will be observed that the walls 4 and 5 of the oven have the upper edges thereof cut away whereby the wall 4 is of less height than the remaining walls of the oven, and the wall 5, adjacent the wall 4, of such a height as to accommodate a lowered or depressed end 28 of the top wall 6 of the over.

The top 16 of the stove casing extends beyond the end of the stove proper and is provided witha rectangular opening 29 having the edges thereof flanged, as at 30, to

provide a seat for grids .(not shown). The opening 29 extends over an end of the oven and the top wall 16 of the casing, at the inner end of the opening 29, is connected by a compound curved housing wall 31 to the upper edge of the casing wall 11. The housing wall 31 therefore coiiperate's with the lowered or depressed end 28 of the top wall 6 of the oven in providing a flue 32 establishing communication between the upper end of the flue 12 and top horizontal flue 17. The housing wall 31, is an important adjunct as it coiiperates with a I disposed and has .burner housing 33 in providing a l'ar e comends thereof, is formed with a raised center 39 for the two fold purpose, first, of giving more room for the passage of smoke 'rom the flue 17; also containing a trap door 40 permitting access to the flue 12 for cleaning, and secondly forming pockets 38 for 'burners. The wall 31, in which the pockets are formed, is provided with protuberances or shoulders 41 cotiperating with shoulders 42 of the end wall of the housing 33' in supporting longitudinally disposed burner holders 43. These holders are provided with openings for depending positioning pins 44 carried by the burners 34 and in addition to these positioning pins said burners have depending pins orfeet 45 resting upon the holders 43. The pins 45 coiiperate with the holders 43 in supporting the burners in an elevated position within the housing 33, thereby providing sufficient clearance for the admission of air to the housing to insure a perfect combustion or uniform operation of theburners. The gas burners are of the ordinaryand well known design for artificial or natural gas and said burners are conveniently disposed to serve grids or openings of the housing 33. The front wall and other walls of the housing 33 is closed to the admission of air. Valve nozzles 48 admitting gas from a header 49 to the burners '34 pass through the front wall and project inside. The burners are provided with air mixers 47 and with an" opening to fit over the nozzles thereby supporting that end of the burners; A dust pan 80 rests over the opening 35 in thesbot- ,tom of the housing 33 but-is raised from the bottom "to admit air flowing around .said panwhich supplies the mixers 47 and the burners 34. These valves and headers are of the ordinary and well known type and are supported by brackets-50 connected to the top wall 16 of the stove casing. One end of the header 49 is connected to a gas supply pipe 51 that extends rearwardly at the side ofthe'housing 33, and downwardly funder the housing in parallelism with the'jcasing wall 11 of the stove'for a purpose that will presently appear. I p 4 The bottom of-the housing 33, at the rear end thereof, has an inclined portion 52- and the rear wall of the housiiig has an opening 53 throughout its length. Suitably secured to the inclined portion 52 of the housing is a flue box 54 in communication with the housing through the medium of the open rear end thereof; The flue box 54 is 'fitted under the top wall 16 of the stove casing and extends in proximity to the chimney flue 20, as. best shown in Fig. 2. The chimney flue 20 has an opening in communication with the end of the flue box 54 through the medium of a conduit member 55, said member being secured to the outer side of the chimney fine 20 and overlapping the open end of the flue box 54, as best shown in Figs. 1 and 2.

The conduit'member 55 provides a smoke flue from the flue box bl to the chimney flue and in the open end of the flue box is an equalizing damper 56 which opens into the flue to a horizontal position. The damper 56 is in the form of a shutter havmg a rock shaft 57 journaled in the bottom of the flue box, and the outer end of said rock shaft has a crank 58 connected to an actuating member 59. The member 59 extends through the top wall or plate 16 of the stov casing in proximity to the chimney 22 and the crank shaft :26 of the damper At the upper end of the member 59 is a handle 60 in the form of a plate or cross head upon which there is embossed or otherwise marked directions as to the use of the equalizing damper. For instance, flUp Gas-Down Coal thereby indicating that when the member 59 is raised the equalizing damper aliis open to perinit of gas being used in connection with the stove, and that when the member 59 is lowered the equaliz- Y ing damper 5G is closed to permit of coal being used as a heating or cooking agent of the stove.

Referring now to the use of artificial or natural gas in connection with the oven of the stove structure, see Figs. 3 and 5. Extending into the hollow tube 9 is a burner pipe (51 arranged along the bottom of the stove structure and connected to the gas supply pipe 51 by an air mixer 62, a valve 63 anda T connection 64. The end of the burner pipe (51, within the support 9, is provided with diametrically opposed lugs 65 engaging sockets 66 provided therefor in the top of the support 9. The pipe I51 terminates below the bottom wall 3 of the oven and detachably mounted upon the end of said pipe is the socket member 67 of a gas burner 68. The gas burner 68 is horizontally disposed above the bottom wall 3 of the oven, and this is an essential feature since the elevation of the gas burner permits of sufficient air entering through the tube to insure perfect combustion. As a matter of fact, it has been determined by experiment and actual use of the stove that with the gas burner flush in thebottom of the oven or below the bottom that there is an imperfect combustion and poor baking.

\Vith the tube 9 and the hollow coneshaped tube 10a sufficient quantity of air can reach the burner and the products of combustion are deflected or disseminated through the oven by a false bottom or spreader member 69 arranged upon the bottom 3 of the oven. The products of combustion eventually escape through openings '70 provided therefor in the rear wall 5 of the oven into the exit flue 20.

To use coal or other solid fuel in connection with this stove, the gas burner 68 is removed from the oven and the closure 27.

placed in position. The equalizing damper a6 is closed. The products of combustion or 'heat units can then pass over, around and under the oven similar to an ordinary coal stove, this being accomplished through the medium of the various flues surrounding the oven. But the cover 27 is not heated and would cause a cold spot were it not for the outward sloping walls of the tube 10 which radiate heat so as to bake articles placed over the cover 27. To use gas in connection with the oven, the closure 27 is removed and the gas burner (38 and spreader 69 placed in position as shown in Fig; 3. The equalizing damper 56 is opened and the products of combustion or heated air escape through the openings 70 into the flue 20. hen the burners 3t are used in connection with artificial gas, for instance for boiling, the.prodnets of combustion rise into the room through the open grids on 'which'a kettle sets. When using natural gas the grids are replaced by a solid top because of an ofl'ensive odor, and the products of combustion will be carried off by the flue box through the chimney or exhaust pipe, it being understood that the equalizing damper is open to permit the passage-of the products of combustion and that it is only when coal is used that the equalizing damper is closed to give the full chimney draft to the coal burning unit. The equalizing damper prevents variations in the chimney draft from effecting the operation of the range oven with gas. In using either kind of gas in a range having an oven, a gas burner therein, a walled opening for air through the horizontal bottom flue of the oven and exhaust openings from the oven into the chimney flue, any variations in the pull' of the chimney or a down draft therein, will derange the baking of the oven. A gas range oven when not connected to a chimney is constructed to work perfectly, but when connected to a chimney the variations therein will Very often spoil baking whether the chimney has too strong a .draft and pulls the heat out of the oven too rapidly, or whether it has a back draft and smother the burner, These irregularities are taken care of by the equalizing damper, which when open admits air from the room into the chimney flue if the draft is too strong, and if the back draft occurs the downward current finds av vent through the equalizing damper into the room and does not allow the back draft to interfere with the oven.

The levity of the'products of combustion in the oven causes a steady flow of fresh air to the burner through the tube 9 and the iical tubelO into the oven and through the openings 70 into chimney flues 20.

It is thought that the operation and utility of the combined coal and gas range will be apparent without further description, and while in thedrawings there is illustrated a preferred embodiment of the invention, it is to be understood that the structural elements are susceptible to such changes, as in the size, shape and manner of assemblage as fall within the scope of the appended claims.

What I claim is 1. In a combination coal and gas range,

an oven surrounded on the top, end and bottom .by smoke flues for coal, a walled opening through the bottomsmoke flue for the entrance of external air, a gas supply pipe in such opening, a gas burner removable. from said supply pipe, said burner beingot alarger diameter than said opening a and located above the bottom plate of said 'oven, leaving a free air space between said rner and said oven bottom. 2. In a combmation coal and gas an oven surrounded on the top, end and bottom with smoke flues for coal, a smoke flue on the back of said oven connected to the bottom smoke flue and a smoke exit in the .top of said range, the oven having an opening through the back wall in said back smoke flue, a chamber, containing gas burners, located over said smoke flue above the oven, and open to the air of the room,

'. a direct damper opening from the smoke flue above said oven into the smoke flue back of the oven, an equalizing damper under the stove top connecting said smoke flue with said burner chamber and thence with the air of the room, a walled opening through the bottom smoke flue, and an oven gas burner located above the oven bottom..

3. A combined coal and gas range comrange,

prising a stove structure, an oven having a hollow tapering opening through its bottom, a closure supported within the conical openmg below the level of the oven bottom allowing radiated heat from the conical sides o the opening to be radiated into the oven.

at. In a combination coal and gas range having top .and end-smoke flues, a burner chamber under the stove top and having a wall over the top and end smoke flues, said wall having concaveend portions restricting the top flues and a convex portion intermediate the concave portions of said wall and provicledv'itli an opening, a door normally closing said'opening, said convex portion of said wall increasing the cross sectional area of said top flue to compensate for the restricted portions of said flue, whereby said top flue has the conduit capacity of said end flue, and a burner abov'e'each concave portion of said wall.

5. In a combination coal and gas range, a

substantially rectangular oven having topand'end flues with the top of said oven de- I pressedbetween said top and end flues, a burner chamber under the stove top iand having a wall in parallelism with the depressed, portion of said oven top, said chamber wall having a convex intermediate portion provided with an opening, a door normally closing said opening, and a burner, 

